textproduct: Quad Cities

KEY MESSAGES

- Mostly cloudy skies will continue into the weekend with spotty light rain showers. Precipitation chances increase further towards mid-next week when a larger and wetter system moves in.

- Temperatures will continue to be cooler than average into the weekend, moderating back to seasonable or even slightly above normal levels next week.

SHORT TERM /THROUGH TONIGHT/

Issued at 230 AM CDT Fri Sep 25 2026

The latest water vapor loop was showing ridge-riding short wave scooting southeastward acrs western WI into northern IA ATTM, with a secondary vort max acrs south central NE. These features flanking an upper ridge omega block, but will be at least light precip makers for the local area with spotty light showers and sprinkles for much of the day until late afternoon. This is when the upper ridge gets temporarily re-enforced from the west acrs the area before another longer wave upper trof acrs the west central plains takes aim at undercutting the omega block late tonight into Saturday. This precip continuing to run into low to mid level easterly fetch will make for light QPF totals of a tenth of an inch or less today, with the precip struggling to reach the sfc as it pushes eastward into the IL side. Not the nicest of Fridays with clouds and occasional light precip keeping temps down in the 60s.

Tonight..again expect an evening lull in precip making processes unless a cloud deck can saturate low enough to allow for some spotty drizzle. As the above mentioned central plains trof sweeps acrs the southwest half of IA late tonight, pre-system warm air advection (WAA) wing should create a band of sctrd elevated showers pushing into the far southwestern CWA before dawn. Don't anticipate any thunder with this late night activity as better mid level CAPEs and lapse rates remain off to the west of the DVN CWA. Overnight lows generally in the 50s.

LONG TERM /SATURDAY THROUGH THURSDAY/

Issued at 230 AM CDT Fri Sep 25 2026

Saturday...Large east coast cyclone and blocked pattern acrs the eastern 2/3's of the CONUS to hold up the passing trof acrs the region on Saturday, and thus clouds with sctrd showers. Still expect more activity and shower maintenance acrs IA and MO with lingering precip erosion processes as you get further to the east acrs IL. Thus better chance for at least some light rain accums more west of the MS RVR. With drying easterly fetch continuing acrs IL and potentially more cloud/precip breaks there, we may have a temp gradient with warmer highs in the east and cooler highs only in the low 60s in the far western CWA. Showery, misty night looks in store for Saturday night with the upper trof lingering overhead.

Sunday and beyond...The signal is for the precipitation to wane Sunday morning as mid-level ridging reinvigorates and weakens the shortwave forcing. With the cloud cover and rain in place, temperatures will feel cooler than average, with highs in the 60s.

Sunday night through Monday appears likely to be a dry period thanks to high pressure dominating over the region. Partly to mostly sunny skies and southeasterly flow Monday should result in the return of upper 60s to lower 70s for high temperatures.

This period of dryness will come to an end mid-week as a larger system builds in sometime around late Tuesday/Wednesday. A longer wave trough, with models showing a strong tropical connection to the systems in the eastern Pacific, should translate through the area, although the exact timing of associated precipitation remains uncertain. However, there is a strong signal for abundant moisture with this system, with Pwat values of around 1.5 to 2 inches. Exceedance probabilities of 1.6 inch Pwats are around 50-70% per the latest LREF ensemble, supporting a period of heavy rainfall potential. Now, it remains unclear how long this period of rainfall will last into Wednesday, given differing end times of precip per the GFS/ECMWF/CMC global model solutions as some guidance shows a large progressive longer wave trough sweeping across the mid-CONUS versus a slower cut-off low with multiple rounds of rains mid to late week. The latter scenario would be more concerning for heavy rainfall/flash flooding, given wet antecedent conditions, so this mid-week system does bear watching.

AVIATION /12Z TAFS THROUGH 12Z SATURDAY/

Issued at 608 AM CDT Fri Sep 25 2026

Warm advection aloft, generally around 8000-10000 ft, will continue to result in opaque mid clouds through the period, with occasional light showers, capable of lowering visibility to 4-6sm, and cigs to 2000 ft at times this morning. By late afternoon, this forcing is expected to weaken, and that will allow east winds to bring in more dry low level air, with cigs increasing back to VFR for tonight. Some spotty rain showers remain possible, but most hours will be dry tonight.

DVN WATCHES/WARNINGS/ADVISORIES

IA...None. IL...None. MO...None.